Integrated washing and sterilization process

ABSTRACT

A method for cleaning and sterilizing a medical device comprises the steps of: placing the device into a container; cleaning the device in the container with a cleaning solution; rinsing the device in the container with a rinse solution; and vaporizing a liquid substance in the container to create a sterilant vapor and contacting the device with the vapor to effect sterilization of the device.

[0001] This application is a continuation-in-part of U.S. applicationSer. No. 09/746,106 filed Dec. 22, 2000 which is a continuation-in-partof U.S. Pat. No. 6,203,756 issued on Mar. 20, 2001, each of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] This invention relates to systems and processes for chemicalsterilizing or disinfecting medical devices.

[0003] Medical instruments have traditionally been sterilized ordisinfected using either heat such as is provided by steam, or achemical in liquid, gas, or vapor state.

[0004] Prior to sterilization or disinfection, the instruments to betreated are usually first cleaned and then sterilized or disinfected.Several devices and methods have been developed for washing andsterilizing a device in a single process within a single container andwithout having to transfer the device from a washing apparatus to asterilizing apparatus. Heretofore these applications have been limitedto processes employing liquid based sterilants.

[0005] U.S. Pat. No. 5,443,801 discloses a transportablecleaning/sterilizing apparatus and method for inside-outside washing andsterilization of medical/dental instruments. The apparatus functions infour sequential cycles: wash, rinse, sterilize, and dry. Thesterilization step is conducted using ozonated and purified water, andthe drying step is accomplished by injecting ozonated/deozonated sterilewarm dry oxygen, or sterile inert gas into and exhausted from the washchamber under a positive pressure relative to atmospheric. In thisprocess, the device has to be rinsed with purified water after it issterilized to remove sterilant residue before drying step.

[0006] U.S. Pat. No. 5,505,218 to Steinhauser et al. discloses a devicefor cleaning, disinfecting and maintaining medical or dentalinstruments. The device has a pot-shaped container with a multiplicityof mountings in the interior of the container each for one of toolholder, a water supply system, a compressed air supply system, and anultrasonic transducer. The disinfection is conducted with heated water,and the drying is conducted with hot compressed air. This system is notdesigned for sterilization.

[0007] U.S. Pat. No. 5,279,799 to Moser et al. discloses apparatus forcleaning and testing endoscopes by injecting pressurized air into thesheath and pressurized air and washing liquid into the ducts. A washingchamber is provided which contains retractable cages to hold theendoscopes during cleaning and testing. This process includes washing,disinfecting, final rinsing with purified water, and air drying theducts of a tubular article. A number of filters are involved in thissystem, and this system is not designed for sterilization.

[0008] One disadvantage of the cleaning/sterilizing orcleaning/disinfecting systems of the prior art as discussed above isthat, after the device is sterilized or disinfected and before it isdried, the device has to be rinsed with purified water to removedisinfectant or sterilant residues. A so-called bacteria filter isusually used to filter the water to remove particulates and bacteria.Typically, a two-stage filtering system is utilized, for example, afirst stage has a 2-5 micron filter and a second stage has a 0.1-0.2micron filter. However, virus can be smaller than 0.1 micron. This meansthe virus can penetrate the filtering system recontaminating thesterilized device in the final rinsing process. Another problemassociated with the use of a bacteria filter is that bacteria can formbiofilms in the filter which are difficult to sterilize and, thus,become a new potential source of contamination. In U.S. Pat. No.6,103,189 to Kralovic attempts to solve the problem of getting sterilewater by using a dilute solution of the sterilant to rinse the devices.This has the potential to leave residual sterilant on the devices.

SUMMARY OF THE INVENTION

[0009] A method according to the present invention for cleaning andsterilizing a medical device comprises the steps of: placing the deviceinto a container; cleaning the device in the container with a cleaningsolution; rinsing the device in the container with a rinse solution; andvaporizing a liquid substance in the container to create a sterilantvapor and contacting the device with the vapor to effect sterilizationof the device.

[0010] Preferably, the method further comprises storing the device inthe container in sterile form.

[0011] In one preferred aspect of the invention the liquid substancecomprises a retained portion of the rinse solution. The rinse solutioncan comprise a chemical sterilant. Preferably the chemical sterilantcomprises hydrogen peroxide.

[0012] The liquid substance can comprise a chemical sterilant.Preferably the chemical sterilant comprises hydrogen peroxide.Alternatively, the liquid substance can comprise water which isvaporized to produce a sterilant vapor of steam.

[0013] In one preferred embodiment, the liquid substance is introducedas a mist.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1a is a schematic diagram of a container used in acleaning/sterilizing process of the present invention.

[0015]FIG. 1b is a schematic diagram of a stirrer with fluid inlets usedin the container of FIG. 1.

[0016]FIG. 1c is a schematic diagram of a gas-permeable butmicroorganism-impermeable barrier installed in a vacuum port of thecontainer of FIG. 1.

[0017]FIG. 1d is a schematic diagram of a container placed in a vacuumchamber used in a cleaning/sterilizing process of the present invention.

[0018]FIG. 1e is a schematic diagram of a container with fluid jettubes.

[0019]FIG. 2 is a schematic diagram of a container with an adapter usedin the cleaning/sterilizing process of the present invention.

[0020]FIG. 3a is a schematic diagram of a container with an interfaceused in the cleaning/sterilizing process of the present invention.

[0021]FIG. 3b is a schematic diagram of a shutter used in the interfaceof the container of FIG. 3a.

[0022]FIG. 3c is a schematic diagram of a iris valve used in theinterface of the container of FIG. 3a.

[0023]FIGS. 3d, 3 e, and 3 f are schematic diagrams of two platesforming an opening in the interface of the container of FIG. 3a.

[0024]FIG. 3g is schematic diagram of an interface of the container ofFIG. 3a.

[0025]FIG. 4 is a schematic diagram of a container placed in a vacuumchamber used in the process of the present invention.

[0026]FIG. 5a is a schematic diagram of a container having two holdersin an interface.

[0027]FIGS. 5b and 5 c are schematic diagrams of two holders of thecontainer shown in FIG. 5a holding a lumen device.

[0028]FIG. 5d is a schematic diagram of an interface of a container withmultiple openings.

[0029]FIG. 6 is a schematic diagram of a container separated into threeenclosures by two interfaces according to the present invention.

[0030]FIG. 7a is a schematic diagram of a container having an interfaceand a tray across the interface according to the present invention.

[0031]FIGS. 7b and 7 c are cross-sectional views of the container ofFIG. 7a at the location of the interface.

[0032]FIG. 8a is a top view of the container of FIG. 7a.

[0033]FIG. 8b is a top view of a portion of the interface of FIG. 7a.

[0034]FIG. 8c is a top view of the tray of FIG. 7a.

[0035]FIG. 8d is a top view of the container of FIG. 7a without the trayand the interface.

[0036]FIG. 9 is a schematic diagram showing a recycle system forprocessing liquid.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0037] The cleaning/sterilizing or cleaning/disinfecting process of thepresent invention can be carried out with various apparatus andincorporated with various sterilization methods, which are describedbelow.

Method to Deliver a Predetermined Amount of Liquid Sterilant

[0038] This method can be incorporated into the cleaning/sterilizing orcleaning/disinfecting process of the present invention. In order tomaximize the efficiency of a vapor sterilization process, it isimportant and desirable to drain excess sterilant solution and only keepa desired amount of the sterilant solution to vaporize after treating adevice to be sterilized with the sterilant solution.

[0039] According to the present invention, a sterilization container orenclosure may have a surface with wells thereon which define a knownvolume. The well is positioned so that when a liquid sterilant isintroduced onto the surface, a known volume of the liquid sterilantfills the well and when the liquid sterilant is drained from thesurface, the known volume of liquid sterilant remains in the well sothat a subsequent vapor sterilization process can be performed on thedevice with the known volume of liquid sterilant positioned within thesurface. The surface preferably has at least one perforation fordraining the liquid sterilant from the surface. The well formed in thesurface can be curved, flat or angled. Thus, the well can be an inwardlyextending hemispherical projection. The well can also be formed in thesurface as an inwardly extending rectangular projection having roundedends. The well formed in the surface can also be a rectangular boxhaving side walls, defining an opening. Where perforations are provided,they can be disposed adjacent the well, and can be roughly spherical inshape. The upwardly extending projection can include a perforationthereon, which can be on top of the projection or on a side of theprojection. The surface can be a sloped surface, a convex or concavesurface or a V-shaped surface. The surface can be made of a variety ofmaterials including stainless steels, aluminum, aluminum alloys, liquidcrystal polymers, polyesters, polyolefins polymers or fluorinatedpolyolefins. If the surface is comprised of a composite material, thecomposite material can include a filler of high thermal conductivity.Examples of composite materials include a metal-filled polymer, aceramic-filled polymer and a glass-filled polymer. Those materials arealso suitable for the side walls and doors of the sterilizationcontainer.

[0040] A tray with wells with configurations similar to that describedabove can be provided with a container or enclosure. The tray can besecured to the container or removably placed in the container.

Method Based on Diffusion Restricted Environments

[0041] A method of vapor sterilization or disinfection underdiffusion-restricted environments can also be used in corporation withthe cleaning/sterilizing or cleaning/disinfecting process of the presentinvention. In this method, the devices (lumen or non-lumen) to besterilized are pretreated with a sterilant solution, and then exposed topressures less than the vapor pressure of sterilant. Both the exteriorand interior surface areas of a lumen or non-lumen device can beeffectively sterilized by taking advantage of the diffusion-restrictedenvironments within lumens or within a container or enclosure.

[0042] As used herein, a “diffusion-restricted” area refers to any oneor more of the following properties: (1) the ability of the area of anarticle placed within the sterilization system of the present inventionto retain 0.17 mg/L or more hydrogen peroxide after one hour at 40° C.and 10 torr; (2) having the same or more diffusion restriction thanprovided by a single entry/exit port of 9 mm or less in internaldiameter and 1 cm or greater in length; (3) having the same or morediffusion restriction than provided by a lumen 27 cm in length andhaving an internal diameter of 3 mm; (4) having the same or morediffusion restriction than provided by a lumen having a ratio of lengthto internal diameter greater than 50; (5) the ability of an articleplaced within the sterilization system of the present invention toretain 17% or more of the starting 1 mg/L hydrogen peroxide solutioninitially placed therein after one hour at 40° C. and 10 torr; or (6)being sufficiently diffusion-restricted to completely sterilize astainless steel blade within a 2.2 cm by 60 cm glass tube having arubber stopper with a 1 mm by 50 cm stainless steel exit tube therein ata vacuum of 10 torr for one hour at 40° C. in accordance with thepresent invention. It is acknowledged that characteristics (1) and (5)will vary depending on the initial concentration of hydrogen peroxideplaced into the article; however, this can be readily determined by onehaving ordinary skill in the art.

[0043] This method includes the steps of contacting the exterior andinterior of a device with a sterilant solution, and then exposing thedevice to a negative pressure or vacuum for a period of time sufficientto effect complete sterilization. For example, when 1 mg/L of hydrogenperoxide is used as sterilant, if the exposing step is conducted for 1hour at 40° C. and 10 torr, the diffusion restricted area preferablyretains 0.17 mg/L or more hydrogen peroxide, or retains 17% or more ofthe hydrogen peroxide placed therein after the exposing step. In certainpreferred embodiments, the diffusion-restricted area has the same ormore diffusion restriction than provided by a lumen 27 cm in length andan internal diameter of 3 mm, or has the same or more diffusionrestriction than provided by a lumen having a ratio of length tointernal diameter greater than 50. The contacting step can be performedby either a direct or an indirect contact procedure. Direct contactingincludes methods such as injection, static soak, flow-through,condensation of a vapor, or aerosol spray, or mist spray. Any othermethods involving physically contacting the devices to be sterilizedwith a sterilant would be considered direct contacting. Indirectcontacting includes those methods in which sterilant is introduced intothe chamber or container, but not directly on or on the devices to besterilized. The exposing step is preferably performed for 60 minutes orless, and is preferably performed at a pressure less than the vaporpressure of the sterilant. Thus, the preferred pressure range underconditions of the present invention is between 0 and 100 torr. Theexposing step can include the step of heating the device, such as byheating the container in which the exposing step occurs. The containercan be heated to about 40° C. to about 55° C. Alternatively, thesterilant solution can be heated, such as to a temperature of about 40°C. to about 55° C. Optionally, the step of exposing the device to aplasma can be conducted during the step of exposing the device tonegative pressure or vacuum. In one embodiment employing exposure toplasma, the method is performed within a first chamber and the plasma isgenerated in a second separate chamber. This embodiment furthercomprises the step of flowing the plasma into the first chamber.Advantageously, the contacting and/or exposing steps of the method canbe repeated one or more times.

[0044] Method Based on Controlled Pump-Down Rate

[0045] The cleaning/sterilizing process of the present invention canalso be carried out in cooperation with a controlled pump down methodwithout relying on a diffusion-restricted environment.

[0046] Effective sterilization results similar to those created indiffusion-restricted environments can be created through controlling theevacuation rate of a chamber or container in which devices to besterilized are placed. Thus, in one embodiment of the present invention,this controlled pump-down rate method comprises the steps of contactingthe device with a liquid sterilant at a first pressure; draining excessliquid sterilant to retain a predetermined amount of the sterilant, anddecreasing the pressure of the chamber to a second pressure below thevapor pressure of the liquid sterilant in which at least a portion ofthe decrease in pressure below about the vapor pressure of the liquidsterilant occurs at a pump down rate of less than 0.8 liters per second,calculated based on the time required to evacuate the chamber fromatmospheric pressure to 20 torr when the chamber is empty and dry, i.e.when the chamber has neither devices to be sterilized nor a visiblequantity of liquid within it. According to one aspect of this preferredembodiment, at least the decrease in pressure below about two times thevapor pressure of the liquid sterilant occurs at a pump down rate ofless than 0.8 liters per second. According to another embodiment, thedecrease in pressure below about four times the vapor pressure of theliquid sterilant occurs at a pump down rate of less than 0.8 liters persecond. Preferably, the pump down rate is 0.6 liters per second or less;more preferably, 0.4 liters per second or less; and most preferably, 0.2liters per second or less. Advantageously, the first pressure isatmospheric pressure. Preferably, the liquid sterilant is hydrogenperoxide. The hydrogen peroxide usually is a solution as used in theart, preferably it is a 3-60% solution. The device can be a lumen ornon-lumen medical instrument.

[0047] The present invention can also incorporate a method forsterilizing a device comprising the steps of (a) contacting the devicewith liquid sterilant at a first pressure; (b) retaining a predeterminedamount of the liquid sterilant in the container; (c) pumping down thecontainer or chamber to a second pressure which is lower than the firstpressure at a first rate; and (d) pumping down the container or chamberto a third pressure which is lower than the second pressure, wherein atleast a portion of the pumping down to the third pressure is at a secondrate which is slower than the first rate. The pump down rate eitherabove and/or below the second pressure can be constant or variable. Incertain embodiments, the pump down rate either above and/or below thesecond pressure is reduced in stepwise fashion. Preferably, the secondpressure is greater than or equal to about the vapor pressure of theliquid sterilant; more preferably, the second pressure is greater thanor equal to about two times the vapor pressure of the liquid sterilant;most preferably, the second pressure is greater than or equal to aboutfour times the vapor pressure of the liquid sterilant. Advantageously,the pump down rate in step (d) is 0.8 liters/sec or less; moreadvantageously 0.6 liters/sec or less; even more advantageously 0.4liters/sec or less; and most advantageously 0.2 liters/sec or less,calculated based on the time required to evacuate the chamber fromatmospheric pressure to 20 torr under empty and dry conditions.Preferably, the liquid sterilant is hydrogen peroxide. In anotherembodiment, the device is a medical instrument having a lumen.Preferably, the pumping down of step (c) reduces the pressure to lessthan about three times, more preferably to less than about two times,the vapor pressure of the liquid sterilant.

[0048] Another suitable method includes contacting the device withliquid sterilant, retaining a predetermined amount of the liquidsterilant in the container, and reducing the pressure of the chamberwhile regulating the pump down rate so as to control the evaporationrate of sterilant in the chamber. In any of the methods described above,the contacting step may comprise application of liquid or condensedvapor. These methods described above may additionally comprise furtherevacuating the chamber to remove residual sterilant. Further, thesemethods described above may additionally comprise exposing the device toplasma to remove residual sterilant or enhance sterilization efficacy.The contacting step in these methods can be either by direct or indirectcontacting. As stated herein, indirect contacting involves introducingsterilant into the chamber without directly contacting the device to besterilized.

Two Step Pump-Down Method

[0049] A two step pump down sterilization method can also be used incooperation with the cleaning/sterilizing process of the presentinvention. This method comprises the steps of contacting a device withliquid sterilant; draining excess liquid sterilant to retain apredetermined amount of the sterilant; bringing the pressure of thechamber to a first pressure range at which the liquid sterilant isvaporized from non-diffusion restricted area of the device to sterilizethe non-diffusion restricted area; bringing the pressure of the chamberto a second pressure range at which the liquid sterilant is vaporizedfrom diffusion restricted area of the device to sterilize the diffusionrestricted area, wherein the minimum pressure in the second pressurerange is lower than the maximum pressure in the first pressure range.

[0050] Preferably, the first pressure range is from 20 to 760 torr; morepreferably, the first pressure range is 20 to 80 torr; most preferably,the first pressure range is 40-50 torr. Advantageously, the secondpressure range is 1-30 torr; more advantageously, the second pressurerange is 5-10 torr. In one preferred embodiment, the device includes adiffusion-restricted environment. Preferably, the device is a medicalinstrument with a lumen. Advantageously, the sterilant is hydrogenperoxide. According to another aspect of this preferred embodiment, thechamber is at a set temperature and wherein the first pressure ispreferably lower than the vapor pressure of the sterilant at the settemperature. Preferably, the pressure of the chamber is maintainedconstant at the first pressure for a time period sufficient to sterilizethe non-diffusion restricted area. Advantageously, the pressure of thechamber is maintained constant at the second pressure for a time periodsufficient to sterilize the diffusion restricted area. The pressure ofthe chamber may be permitted to increase after reaching the first orsecond pressure range as a result of vaporization of the sterilantwithin the chamber. Alternatively, the pressure of the chamber ispermitted to decrease after reaching the first or second pressurethrough pumping of the chamber at a rate slower than used to decreasethe pressure between the first and second pressure ranges. Preferably,the contacting step is with liquid, condensed vapor, or mist. The methodcan also include the steps of bringing the pressure to a third pressurelower than the second pressure to remove residual sterilant and/orexposing the device to plasma to remove residual sterilant or enhancesterilization efficacy.

Method Involving Direct Flow Through a Lumen of the Device to BeSterilized

[0051] A method of directly flowing fluid through a lumen of a medicaldevice to be treated can be incorporated with the cleaning/sterilizingor cleaning/disinfecting process of the present invention. An apparatuscan be used to efficiently clean and sterilize devices with long narrowlumens by flowing a fluid such as a cleaning solution or a sterilant,either in liquid phase or in vapor phase, or a plasma gas directlythrough the lumens of lumen devices to be sterilized.

[0052] The flow of a germicide (solution or vapor), or any cleaningsolution through a lumen of a medical device is driven by a pressuredrop between two open ends of the lumen. The pressure drop can begenerated by applying either a vacuum or a high pressure at one end. Bygenerating a forced flow through a pressure differential other thanrelying on diffusion, the sterilization rate is significantly increasedand less time is needed for a sterilization cycle.

[0053] It is clear that the two ends of the lumen need to be exposed toa pressure differential. This is achieved in the present invention byplacing a sealable interface between two chambers, two enclosures, or acontainer and an enclosure to separate them from each other. Preferably,an opening is provided in the interface and the lumen device to besterilized is placed through the opening so that the lumen serves as aflow path between the two chambers or between the container and theenclosure.

[0054] The opening can be constructed in several ways. One way toachieve this is with a camera shutter approach employing an irisdiaphragm, such as a precision iris diaphragm from Edmund Scientific. Anoptional spring can be used to secure the closure of the shutter. Alsocommercially available is Syntron Iris Flow Control Valve manufacturedby FMC Corporation. This Iris Valve has a sleeve made of Teflon or othersynthetic material defining an aperture. By rotating two ends of thesleeve relative to each other, the aperture can be reduced or increased.Iris diaphragm valves from Kemutec Inc. are also commercially availablewhich can be automatically controlled. Another example is the AirGripperand AirPicker manufactured by Firesone Industrial Products Company.Another way to construct an openable and closeable opening is to employtwo plates. Two edges of the two plates form a gap which can be adjustedby moving the two plates relative to each other. One or more lumendevices are placed through the gap formed between the two plates and thetwo plates are moved together to form a seal around the lumen devices.The edges of the two plates forming the gap can be equipped withcompressible material or expandable material. When expandable materialis used, a fluid source can be provided to expand the expandablematerial. Optionally, a porous material like a sponge or air permeablematerial may be utilized on the edges. In this case some sterilant candiffuse through the porous material to the outer surface of the lumendevice occluded by the closed opening. However, most the sterilant flowsthrough the lumen device. Another usable interface is a hole or a slot,the hole or slot is equipped with gas or liquid inflatable material sothat by inflating the inflatable material on the hole or the slot theopening is reduced and the lumen device is held and sealed. Stillanother option is to place a compressible material on top of anexpandable or inflatable material so as to facilitate the sealing aroundthe lumen device.

[0055] The closing and opening movement of the opening can be controlledmechanically or electronically with any conventional mechanism. Thedegree of opening is adjustable. Thus, it can be sealed to a differentdegree between the opening and the lumen device depending on the desiredpurpose. For example, the opening can form a gas-tight seal, atight-fitting seal, or a loose-fitting seal around the lumen device. Asused herein, a gas-tight seal refers to a seal that substantially stopsliquid and gas flow through the contact area between the opening and thelumen device surface. When a gas-tight seal is employed, preferably thedevice to be sterilized is first pre-cleaned so that the occluded areaby the seal is cleaned before the gas-tight seal is formed. Aloose-fitting seal allows both liquid and gas to flow through the gapbetween the opening and the lumen device surface, and in the meantime isable to maintain a pressure drop across the interface enough to generatea flow through the lumen. A tight-fitting seal allows gas and liquid topenetrate to the contact area between the opening and the lumen devicesurface by diffusion. For example, a tight-fitting seal can be formedwith porous material or textures provided on the contact surface of theopening. Thus, for gas-tight seal the device is held tightly by theclosed opening. In the tight-fitting seal, the closed opening also holdsthe device in position. In the case of a loose-fitting seal, the devicecan move relative to the opening, but is not flashed away.

[0056] The interface can be made openable, closeable, and removable, andmay have more than one opening. In order to promote sterilizationefficiency, all the sterilization apparatus of the present invention canbe further equipped with a heater and/or a plasma.

Specially Designed Containers

[0057] As used herein, the terms “container” and “enclosure” areexchangeable. The present invention provides a container speciallydesigned to eliminate or minimize occlusion area which usuallycorresponds to the contact area between a lumen device surface and aclosed opening of an interface holding the device. The occlusion area ishard to reach by either liquid or vapor because of the close contactbetween two surfaces. Thus, the cleaning and sterilizing of an occlusionarea is adversely affected by such contact. Several approaches have beentaken in the present invention to deal with this occlusion problem.

[0058] One approach is to reduce the contact area by using porousmaterial, textures, sharp projections, or sharp edges on the contactsurface of the opening of the interface, or an adaptor or a connector.In this way, cleaning and sterilizing fluid can either flow or diffuseto most part of the contact surface of the device which is held by theclosed opening fairly tightly and, in the meantime, the contact areabetween the opening and the device surface will impose a resistance tofluid flow high enough to allow a pressure difference to exist betweentwo sides of the interface. Thus, a flow through the lumen of the devicecan be generated and maintained if desired. Another advantage of thisapproach is that the contract area generated through the above means canbe controlled to provide a diffusion restricted environment at thecontact area, which will increase the efficiency of the sterilizationprocess.

[0059] Another approach is to use multiple holders in the opening. Forexample, two holders can be secured to the opening along its passage.Preferably, each of the holders is independently controllable andsealable. During a cleaning or sterilizing process, the two holders arealternately opened and closed, i.e. one is open while the other isclose. In this way, a good seal between the two sides of the interfacecan be maintained and the device can be held tightly during asterilization process. Meanwhile, the contact areas on the devicesurface caused by the two holders are exposed to cleaning or sterilizingfluid alternately.

[0060] Still another approach is the combination of the above twoapproaches. In this approach, the contact surface of the interface, orthe opening, or the holder has multiple contact points. The contactpoints can be projections, teeth, blades, sharp edges, or any othersuitable form and shape. These contact points can be controlledseparately so that a portion of the contact points is made in contactwith the device to be sterilized while the others are not. Byalternately changing the position of the contact points, all theocclusion areas will be exposed to the sterilant. An example of such amultiple contact point structure is a shutter with multiple blades.Those blades can be separately controlled for opening and closing. Thepresent invention also provides a container with a specially designedtray.

[0061] It is often desirable to place the device to be sterilized on atray so that after the device is cleaned and sterilized, it can betransported on the tray without being touched. This reduces the chanceof contamination through touching the device. In the apparatus of thepresent invention, a tray is placed across an openable and closeableinterface between a container and an enclosure or between twocompartments or enclosures, a lumen device is placed on the tray alsoacross the interface. When the interface is in a closed condition, aseal is formed between the opening of the interface and the tray and thelumen device.

[0062] Various apparatus of the present invention which can be used tocarry out the cleaning/sterilizing or cleaning/disinfecting process ofthe present invention is described in more detail by reference to thedrawings. In the following figures like numbers refer to like partsthroughout.

[0063]FIG. 1a shows a container 2 used in a cleaning/sterilizing processof the present invention. Container 2 has a sloped bottom wall 4 leadingto a fluid source 7. A fluid port 6 is provided at the lowest point ofsloped bottom wall 4. Apparently, sloped bottom wall 4 can be configureddifferently and the lowest point can be located in any location withinthe sloped bottom wall 4. For example, instead located in the positionas shown in FIG. 1a, the lowest point, thus the fluid port 6, can belocated at one end or a corner of the sloped bottom wall 4. A valve 8 isprovided at fluid port 6 to control fluid flow in and out container 2.Below sloped bottom wall 4 is a flat lower bottom 14. The lower surfaceof the sloped bottom wall 4 is equipped with a number of transducer 16for providing ultrasonic cleaning. A number of wells 18 are provided ona plate 17 located above the upper surface of the sloped bottom wall 4and below rotating arm 22. Plate 17 can be of any appropriate shape andmade rotatable, so that unwanted liquid retained in wells 18 can beremoved by rotating plate 17. Well 18 can have different shapes and iscapable of retaining a predetermined amount of sterilant as describedearlier. Plate 17 can be removably placed on the upper surface of thesloped bottom wall 4 or secured to the upper surface in a horizontalorientation. One or more stirrer 20 is installed either on sloped bottomwall 4 or on an upper wall 24 or on both. Rotating arm 22 of the stirrer20 can be made hollow or contains channels connecting to an outsidefluid source through the body of the stirrer 20. As shown in FIG. 1b,stirrer 20 can be connected to a water source 21 a, an air source 21 b,and a drain 21 c, each of them is controlled by a valve. Water jet orair jet 26 can be provided through the channels of rotating arm 22.Container 2 can also be made of jacket walls with holes thereon so thatthe water or air jet can be provided through those holes opened on thejacket walls. Container 2 also has a lower grid 28 a and an upper grid28 b. Preferably, grid 28 a and 28 b has a flat shape and horizontallyplaced inside container 2 at an upper and a lower position,respectively. A space defined by lower grid 28 a, upper grid 28 b andside walls of container 2 is used to accommodate a device to be treated.A tray 30 can be placed in the space and the device is placed in thetray 30 for cleaning and sterilizing. Stirrer 20 is located either inthe space defined by upper wall 24, upper grid 28 b and side walls ofcontainer 2, or in the space defined by sloped bottom wall 4, lower grid28 a and side walls of container 2, or in both. Container 2 furthercontains a vacuum port 32 located at the upper portion of container 2.Preferably, vacuum port 32 is located on the upper wall 24 of container2 to avoid liquid in container 2 from entering vacuum port 32. Agas-permeable but microorganism-impermeable barrier 34 is secured to thevacuum port 32. Any conventional method can be used to seal barrier 34into vacuum port 32 such as shown in FIG. 1c. In the connection shown inFIG. 1c, barrier 34 is placed in a barrier holder 34 a. The barrierholder 34 a is placed into a seat 34 b formed between two end of twotubes. An O-ring 34 c is provided around holder 34 a. Thus, by clampingthe two ends of the two tubes toward each other barrier 34 is securedand sealed. A valve 36 is provided at vacuum port 32. A vacuum pump 38is connected to vacuum port 32 through valve 36. A detachable connectorcan be provided between valve 36 and vacuum pump 38.

[0064] Container 2 of FIG. 1a can be placed into a vacuum chamber withslight modification. As shown in FIG. 1d, the same container 2 is usedexcept that barrier 34 provided on upper wall 24 is not connecteddirectly to the vacuum port 32 which is provided on the wall of a vacuumchamber 66.

[0065]FIG. 1e shows another way of providing a fluid jet in container 2.Instead of stirrers, several tubes 22 a with small holes thereon aresecured vertically in container 2 to provide a fluid jet such as a waterjet or an air jet. Tube 22 a can be positioned to provide an uniformspray, the orientation and shape of tube 22 a can be determinedaccording specific purposes. The rest parts can be the same as thecontainer of FIG. 1a.

[0066] When using the above described container in thecleaning/sterilizing process of the present invention, one first placesa device into the container 2. The device can be either placed on thelower grid 28 a or placed in tray 30. Two grids 28 a and 28 b set theboundaries for the devices in the container and keep the device frombeing damaged by stirrer 20. The upper grid 28 b is the fluid fill lineto ensure all the devices are immersed in the fluid. Usually the deviceis first pre-cleaned in container 2 by a water jet to remove majority ofsoils, large particles, and other contaminates. During the pre-cleaning,the drain is usually kept open to remove the dirty water containingthose particles and contaminates. Then the device is cleaned. In thisstep a cleaning solution is filled into container 2 through a liquidpump. The cleaning solution can be any conventional cleaning solutionwith enzyme and detergent solution preferred. During the cleaning step,stirrers, water jet, ultrasonics, or other suitable mechanism can beused to facilitate the cleaning process. When the cleaning is complete,the cleaning solution is drained through fluid port 6. A rinse solutionis then introduced into container 2 through fluid port 6. The rinsesolution can be water, alcohols, or other rinse liquid. The rinsing canbe facilitated by stirrers, water jet, air bubbles, or other suitablemechanism. These steps can be repeated if desirable. After the rinsingstep, air can be introduced through stirrer 20 to blow water off thedevice. Then a liquid sterilant is introduced into container 2 from thesame fluid port, and the device is treated with the liquid sterilant fora desired time. Preferably, the liquid sterilant is a hydrogen peroxidesolution or a peracetic acid solution. The main purpose of this step isto treat the device with the liquid sterilant and to provide rightamount of the liquid sterilant. The sterilization is achieved mainly innext step. If necessary, excess of the liquid sterilant can be drainedfrom container 2, and a predetermined amount of the liquid sterilantwill be retained by the wells 18. This amount of liquid sterilant isdetermined based on the size of the load, the container, and the vacuumchamber. At this point, vacuum pump 38 is turned on and vacuum isapplied to container 2 through vacuum port 32. In this step, thediffusion restricted environment method, the controlled pump down ratemethod, the two step pump down method discussed previously can beemployed to achieve good sterilization results. When the sterilizationis finished, container 2 is detached from the vacuum system, the devicecan be kept in container 2 and stored for future use. The sterility ofthe sterilized device is maintained in container 2 because container 2is sealed except for the gas-permeable but microorganism-impermeablebarrier 34. In one embodiment, valve 36 is closed when the pressure incontainer 2 is lower than atmospheric pressure and container 2 includingthe sterilized device is stored for use. This procedure provides afurther means to check if the sterility of the device is well maintainedin the container. If the container 2 is still under a pressure below theatmosphere before next use of the device, that means no air leaking intocontainer 2 and, thus, no microorganism can enter container 2 during thestorage. Any one of the above steps can be repeated if desirable. Thesterilizing step can also be replaced with a disinfecting step by usinga proper germicide.

[0067]FIG. 2 shows a container having adapters for connecting lumendevices. Similar to the container of FIG. 1a, container 2 shown in FIG.2 has a sloped bottom wall 4 with a first fluid port 6 at the lowestpoint of the sloped bottom wall 4. Several stirrers are installed on thesloped bottom wall 4. A flat sheet metal grid 28 a is horizontallylocated at the lower portion of container 2. Grid 28 a, sloped bottomwall 4, and side walls of container 2 define a space accommodatingstirrer 20 and wells 18 on plate 17. An adapter 40 is connected to asecond fluid port 42 at one end and the other end for receiving a lumendevice 46. A gas-tight seal, tight-fitting, or loose-fitting betweenadapter 40 and lumen device 46 can be formed. Adapter 40 can be anysuitable conventional adapters used in the art. Preferably, the secondfluid port 42 is located above grid 28 a. Second fluid port 42 is alsoconnected to a source 44 for generating a pressure difference betweenthe two ends of a lumen device 46 which is connected with the secondfluid port 42 through adapter 40. Source 44 can be a liquid pump forgenerating negative pressure, or a positive pressure. Lumen device 46 isplaced on top of the grid 28 a. Like the container shown in FIG. 1a,container 2 of FIG. 2 also has a vacuum port 32 with a gas-permeable butmicroorganism-impermeable barrier 34 and a valve 36. The barrier coversthe vacuum port 32 and blocks passage for microorganism, valve 36controls the opening and closing of the vacuum port 32. As shown, fluidport 6 and stirrers 20 are also connected with a tube 9 for drainingfluid from container 2 or supplying fluid jet to stirrer 20. One end oftube 9 leads to a waste fluid collector, the other end is connected topump 44.

[0068]FIG. 3a shows a container 2 separated into a first enclosure 50 aand a second enclosure 50 b by an interface 52. As shown both enclosure50 a and 50 b have a sloped bottom wall 4 with stirrer 20 securedthereon, a flat sheet grid 28 a horizontally positioned at lower portionof enclosure 50 a and 50 b, and a fluid port 6, respectively. A pump 54is provided between the two fluid ports 6. A vacuum port 32 is providedat the upper portion of enclosure 50 a and 50 b. A gas-permeable butmicroorganism-impermeable barrier 34 is connected to the vacuum port 32to stop microorganism from entering enclosure 50 a and 50 b throughvacuum port 32. Vacuum port 32 is also equipped with a valve 36 and asource 44 for generating pressure difference and providing vacuum.Preferably, source 44 is a vacuum pump for providing negative pressureor compressed air for providing positive pressure. Interface 52 has acontrollable opening 56 (also referred as holder). Lumen device 46 isplaced across opening 56 partly in enclosure 50 a and partly inenclosure 50 b. Opening 56 can be configured differently. For example,opening 56 can be made of a shutter 58 such as an iris diaphragm asshown in FIG. 3b, and the opening and closing of opening 56 can becontrolled manually or automatically. In one embodiment, the blades ofshutter 58 (eight blades are shown in FIG. 3b), can be divided into twogroups. For example, each group contains four blades not next to eachother. These two groups of blades are controlled separately by acontroller so that while one group is in the close position holding thedevice to be sterilized the other group is in open position allowing thesterilant to sterilize the area occluded by the blades when the bladesare in closed position. Another example of shutter 58 is the SyntronIris Flow Control Valve (by FMC Corporation) or the Iris diaphragmvalves (Kemutec Inc.) as shown in FIG. 3c. Briefly, Iris valve 58 a hasa cylindrical sleeve 90 with two retaining rings 92 located at two endsof the cylindrical sleeve 90. Sleeve 90 is made of Teflon or othersuitable plastic or rubber material. When in use, a lumen device isinserted through an aperture 94 of cylindrical sleeve 90. A firstretaining ring 92 is secured and sealed to opening 56, a secondretaining ring 92 is free to rotate and coupled to interface 52 througha conventional mechanical mechanism (not shown) so that the turning ofthe second retaining ring 92 can be controlled mechanically orelectronically from outside container 2. By rotating the retaining rings92 relative to each other, the diameter of aperture 94 of thecylindrical sleeve 90 can be increased or reduced, or totally shut offIf desirable, more than one shutter can be provided in the interface 52.

[0069] Opening 56 also can be a slot or a gap defined by two plates 59as shown in FIGS. 3d and 3 e. The contact edges or surfaces of plate 59,which form the slot and hold the lumen device 46, are equipped with alayer of expandable material 60 such as silicon, or a layer ofcompressible material 62. The closing, and thus seal around lumen device46, of the slot can be done either by moving plate 59 or expandingexpandable material 60. With a two-plate opening 56, more than one lumendevice can be placed across the opening 56. When expandable orinflatable material is used on plate 59, an expansion fluid source canbe provided to plate 59 to expand the expandable material 60. In oneembodiment, a layer of compressible material 62 is provided on top ofthe layer of expandable material 60 as shown in FIG. 3f. In anotherembodiment, the opening 56 is formed by an upper plate 59 a and a lowerplate 59 b as shown in FIG. 3g. The lower plate 59 b has a rectangularshape with a bottom edge and two side edges being secured and sealed tothe bottom wall and two side walls of container 2, respectively. Theupper plate 59 a also has a rectangular shape and its upper portion ismovably inserted into a housing 53 a. Housing 53 a forms the upperportion of interface 52. A portion of housing 53 a extends along twoside walls of container 2 to the upper edge (or contact surface) oflower plate 59 b, forming two rails 53 b for receiving the two sideedges of upper plate 59 a and guiding the movement of the upper plate 59a. There provided a seal between the upper plate 59 a and the housing 53a and rail 53 b. For example, an O-ring can be used in housing 53 a andrail 53 b to seal the upper plate 59 a. The upper edge of the lowerplate 59 b and the lower edge of the upper plate 59 a are provided witha layer of compressible or expandable material. The movement of theupper plate 59 a can be controlled by any suitable conventional method,mechanically or electrically, form the outside of container 2. Manydifferent configurations and structures can be adopted for the opening56. For example, the contact surface of opening 56 can be made of anuneven surface so that, when opening 56 is closed around a lumen device,the uneven surface will provide passage to allow both liquid and gas topass therethrough while holding the lumen device. Thus, the occlusionarea on the lumen device surface can be significantly reduced. Theuneven surface may have textures, projections, sharp edges, or sharppoints thereon.

[0070] In another embodiment, opening 56 is an aperture equipped with alayer of porous material or with a layer of expandable material and alayer of porous material on top of the expandable material. Opening 56also can be made of an aperture of suitable shape, such as cylindrical,lined with porous material. A shutter is secured to the apertureproviding a steady holding of the lumen device 46 with minimal contactarea or occlusion area.

[0071]FIG. 4 shows a container 2 with an enclose 50 separated by aninterface 52. In this embodiment, the container 2 with the enclosure 50is placed inside and coupled to vacuum chamber 66. Vacuum chamber 66 hasa first vacuum port 68 which is in gas communication with container 2through a gas-permeable but microorganism-impermeable membrane 34installed on the upper wall of container 2, and which is preferablylocated at the upper portion of a side wall of vacuum chamber 66. Avalve 35 is provided above membrane 34 to control the opening andclosing of gas communication of container 2 with outside throughmembrane 34. Vacuum chamber 66 also has a second vacuum port 70connecting to a vacuum port 32 of the enclosure 50 through a valve 36.Preferably, the second vacuum port 70 also located at the upper portionof the side wall of the vacuum chamber and near the first vacuum port68. Valve 36 is preferably located outside the enclosure 50 and insidethe vacuum chamber 66. A detachable connector (not shown) is preferablyprovided between valve 36 and second vacuum port 70 for attaching valve36 to and detaching valve 36 from the second vacuum port 70. The firstand second vacuum ports 68 and 70 are connected to each other outsidethe vacuum chamber 66. A valve 72 is provided at first vacuum port 68 tocontrol flow through the first vacuum port 68. A valve 74 can also beprovided at the common inlet of the first and second vacuum ports 68 and70. A source 44 for generating pressure difference between the two endsof the lumen device 46 is provided at the common inlet of first andsecond vacuum ports 68 and 70. Preferably, source 44 is a vacuum pumpfor generating a negative pressure or compressed air for generating apositive pressure. Vacuum chamber 66 also has a first fluid port 76connecting to a fluid port 6 a of the container 2 through a valve 8 a,and a second fluid port 78 connecting to a fluid port 6 b of theenclosure 50 through a valve 8 b. The first and second fluid ports 76and 78 are located at the lower portion of a side wall of the vacuumchamber 66 and close to each other. The fluid port 6 a is located at thelowest point of a sloped bottom wall 4 a of the container 2. In thisembodiment, the fluid port 6 a is located at one lower corner of thecontainer 2. The fluid port 6 b is located at the lowest point of asloped bottom wall 4 b of the enclosure 50. In this embodiment, thefluid port 6 b is located at one lower corner of the enclosure 50. Adetachable connector can be provided for connecting valve 8 a and 8 b tofirst and second fluid port 76 and 78, respectively. Outside the vacuumchamber 66, first and second fluid ports 76 and 78 are connected to eachother forming a common fluid inlet which is provided with a valve 80. Aliquid pump 54 is also provided between the first and second fluid ports76 and 78 to circulate a fluid between the container 2 and the enclosure50. The container 2 has a lower grid 28 a and an upper grid 28 b.Preferably, the lower grid 28 a and the upper grid 28 b are a flat metalsheet and horizontally positioned at the lower and the upper portion ofthe container 2, respectively. Stirrers 20 are located below the lowergrid 28 a. Interface 52 has an opening (or holder) 56 for holding alumen device 46.

[0072] The opening 56 can be configured in many different ways such asthose described with FIGS. 3b-3 f. On the bottom wall of vacuum chamber66, a plurality of transducer 16 is provided to generate ultrasonics.Accordingly, the space between outer surface of the bottom of container2 and the inner surface of the bottom wall of vacuum chamber 66 isfilled with water or other suitable liquids providing a medium for theultrasonics.

[0073] In using the apparatus with containers and enclosures separatedby an interface in the cleaning/sterilizing or cleaning/disinfectingprocess of the present invention, a lumen device is placed into thecontainer 2 and the enclosure 50 across the interface 52. The opening 56of the interface 52 is then closed manually or automatically. Thus,opening 56 forms a seal around the lumen device. The extent of thesealing can be controlled through different degree of tightening of theopening 56 around the lumen device 46 for different purposes. As definedpreviously, three types of seal can be made between the opening 56 andthe lumen device 46, gas-tight seal, loose-fitting seal andtight-fitting seal. If maximum pressure is intended a gas-tight sealshould be used in this case the container 2 is substantially totallysealed from the enclosure 50, neither gas nor liquid can flow throughthe space between the opening 56 and the lumen device 46. Under manysituations such a gas-tight seal is not necessary. In this case, atight-fitting seal can be used so that a portion of fluid in the systemcan flow or diffuse through the space between the opening 56 and thelumen device 46, but a large portion of the fluid flows through thelumen of the lumen device 46, and the lumen device 46 is still held inposition by the opening 56 during agitation. Loose-fitting will providea opportunity to clean/sterilize the outer surface area of the lumendevice 46 which is otherwise obscured by the opening 56.

[0074] A cleaning solution is then introduced into the container 2 andthe enclosure 50 through fluid port 6 a and 6 b, respectively. Theliquid level in the container 2 and the enclosure 50 is preferably nothigher than the position of the vacuum port 32. A stirrer, a water jetor an air jet can be used to facilitate the cleaning of the outersurface of the lumen device 46. The cleaning solution is also circulatedbetween container 2 and enclosure 50 through the lumen of the lumendevice 46. There are at least two ways to make the circulation. Onemethod is to apply vacuum to the enclosure 50 through second vacuum port70 of vacuum chamber 66 and vacuum port 32 of the enclosure 50 whilekeeping vacuum chamber 66 and container 2 at atmospheric pressure or anypressure higher than that of the enclosure 50. This can be donesimilarly when vacuum chamber 66 is not used. The cleaning fluid thenflows from the container 2 into the enclosure 50 through the lumendevice 46. The liquid pump 54 circulates the cleaning fluid back to thecontainer 2. The opening 56 and the stirrer 20 can be controlled by theelectronic signals from the system. Air bubbles generated from air pump10 can be introduced at this stage to enhance the scrubbing actionduring cleaning. Thus, both the outer surface and the inner surface ofthe lumen device 46 can be cleaned at the same time. Vacuum can beapplied to container 2 to generate a pressure in the container 2 lowerthan that of the enclosure 50. Forced air also can be used to pushliquid through the lumen. If desired, the interior and the exterior ofthe lumen device can be cleaned separately. The cleaning fluid can beremoved from the container 2 and enclosure 50 through the fluid port 6 aand 6 b on the sloped bottom wall 4 a and 4 b. The cleaning fluid in thelumen device 46 can be removed either with vacuum or forced-air.

[0075] The rinsing with water and the treatment with liquid sterilantcan be conducted similarly. When the treatment with a liquid sterilantis complete, the liquid sterilant is drained and a predetermined amountof the liquid sterilant can be retained in the wells. Then vacuum isapplied to chamber 66 and container 2 either through vacuum port 68 or70, or both in a manner described earlier. At least in certain stage,the vacuum should be high enough (or the pressure low enough) tovaporize the remaining sterilant in container 2 to sterilize and dry thedevice simultaneously. A plasma can be used as an option to enhance theefficacy and/or to remove the sterilant residual. After thesterilization is completed, the chamber is vented and the container isready to be retrieved from the chamber. If desired, valve 35 can beclosed at any pressure below the atmospheric pressure and the sterilizeddevice is kept in container 2 under a subatmospheric pressure. This mayserve as an indication of a well maintained sterility, i.e. if thevacuum still exists when container is opened after a period of time ofstorage that indicates the sterility of the sterilized device is wellkept. The pressure can be monitored and controlled by the pressuresensor on the vacuum chamber 66 or in container 2.

[0076]FIG. 5a shows a container very similar to that shown in FIG. 3aexcept that two holders 100 are used in opening 56 of interface 52. Asshown in FIGS. 5a and 5 b, the two holders 100 are secured to opening 56along lumen device 46 or the passage of opening 56. Each holder 100 issealed to opening 56 in any suitable conventional manner and each holder100 is independently controllable. Holder 100 can be a shutter as theshutter described with FIGS. 3b and 3 c, or made of two plates asdescribed with FIGS. 3d-3 g. FIG. 5b shows two holders 100 of shuttertype holding a lumen device 46. During cleaning or sterilizingoperation, a first holder 100 is first closed and a second holder 100 isopened, then the first holder is opened and the second holder 100 isclosed. Thus, enclosures 50 a and 50 b are always separated or insulatedfrom each other through the engagement of one holder 100 with the device46 and, in the meantime, the two contact surface areas of the device 46occluded by the two holders 100 are exposed alternately.

[0077]FIG. 5c shows two holders 100 of plate type holding a lumen device46. Each of holders 100 can be constructed in the way as describedpreviously with FIGS. 3d-3 g. Preferably, the gap (the opening forpassing the lumen device) formed between the two plates of one holder100 forms an angle with that of the other holder 100 of the two holderstructure. Preferably, the angle is 90 degree as shown in FIG. 5c. Thetwo holders 100 are preferably positioned close enough so that when theexpandable material 60 lined in the gap (opening) is expanded, theexpandable material 60 will also expand outwardly away from the twoplates and become in contact with the other holder 100, thus help sealthe gap of the other holder 100. This configuration provides anadvantage that no complete seal is needed for a single holder, yet agood seal such as a gas-tight seal can be achieved when two such holdersare combined. It has been noted by the applicants that, when acylindrical lumen device is placed across the gap between the two platesof holder 100, areas on the outer surface of the lumen device, where thediameter of the cylindrical lumen device is parallel to the gap, aremore difficult to seal because the expandable material 60 has to expandextra distance to cover those areas. By providing two closely positionedholders 100 with the two gaps forming an angle, the above mentionedareas in each of the two holders can be sealed by the other holder.Therefore, the requirement to the expandable material can be loweredwithout sacrificing the sealing characteristics. FIG. 5d shows anotherembodiment of an interface of the present invention. In this embodiment,the interface 52 contains multiple openings 56 c. This interface 52 mayhave three parts. A first plate 59 c has a plurality of openings 56 cthereon. The cross section of the opening 56 c as viewed from adirection perpendicular to the surface of plate 59 c has an elongateshape with its longitudinal axis extending along a substantiallyvertical direction. Other orientation also can be adopted. Preferably,opening 56 c has a rectangular cross section. The upper side of theopenings 56 c can be made open for easy access to a lumen device. Thecontact surface of opening 56 c is provided with a layer of expandablematerial 60. A second plate 59 d is positioned beside the first plate 59c in parallel. Plate 59 d can be secured and sealed to the bottom andside walls of container 2 with its upper edge or surface equipped with alayer of expandable material 60. A third plate 59 e is located above andaligned with second plate 59 d. The third plate can be made a part ofthe lid for container 2. The lower edge of plate 59 e and the upper edgeof plate 59 d form a gap for passing a lumen device. The edges of thethird plate is also provided with a layer of expandable or other sealingmaterial 60. Preferably, the second plate 59 d and the third plate 59 elie in one vertical plane, and the first plate 59 c lies in anothervertical plane parallel to that containing second plate 59 d and thirdplate 59 e. Preferably, the gap formed between plate 59 d and 59 e formsan angle with openings 56 c, more preferably the angle is a right angle.In one preferred embodiment, the gap between second plate 59 d and thirdplate 59 e has a horizontal orientation, and the openings 56 c have avertical orientation. The distance between the first plate 59 c and thesecond and third plate 59 d and 59 e can be adjusted depending onintended purpose. Preferably, they are closely positioned relative toeach other so that when the expandable material 60 on one plate isexpanded, it will become in contact with the other plate to furtherfacilitate seal around the lumen device passing both the gap betweenplate 59 d and 59 e and the opening 56 c of plate 59 c. Preferably, thedimension and the expandable material layer of opening 56 c isdetermined to allow the opening 56 c to be closed and sealed when theexpandable material is expanded even no lumen device is placed throughthe opening.

[0078]FIG. 6 shows a container 2 has three enclosures 50 a, 50 b, and 50c separated by two interfaces 52 a and 52 b, respectively. Enclosure 50b is located in between and shares interfaces 52 a and 52 b withenclosure 50 a and 50 c. Other parts of the container 2 of FIG. 6 aresimilar to those of the container shown in FIG. 3a, and they areindicated by same numerical references. Two openings 56 a and 56 b arelocated in interface 52 a and 52 b, respectively. Opening 56 a and 56 bcan be of any form as discussed previously. In practice of the processof the present invention, a lumen device 46 is placed across bothopening 56 a and opening 56 b with one end located in enclosure 50 a andthe other end in enclosure 50 c. The advantage of the configuration isto help obtain a large pressure drop between the two ends of the device46. Under certain circumstances, the seal between the opening and thelumen device may be not gas-tight, thus it is difficult to keep a largepressure drop at the two sides of the interface with such a seal. Byadding one intermediate enclosure 50 b, the pressure drop across eachinterface 52 a and 52 b can be kept at a relative low level, yet thetotal pressure between the two ends of the device 46 or, in other words,between enclosure 50 a and enclosure 50 c can be still large enough togenerate desired flow rate through the lumen of the lumen device 46. Ifdesired, one interface 52 a or 52 b can be removed or opened, and inthose cases the container 2 can be operated just like that of FIG. 3a.

[0079]FIG. 7a shows a container 2 separated into an enclosure 50 a andan enclosure 50 b by an interface 52 similar to the container of FIG. 3aexcept that a tray 110 is placed across interface 52 and located in bothenclosure 50 a and enclosure 50 b. The tray 110 shown in FIG. 7a has arectangular shape with four side walls perpendicular to a bottom walldefining a space for receiving a lumen device 46. The side and bottomwalls have open holes thereon. As shown in FIG. 7b, interface 52 can beconfigured to have two parts. The first part forms a tray seat 112extending along an interior periphery of container 2. Tray seat 112 hasa first edge secured and sealed to the interior periphery of container 2and a second edge 114 shaped to receive tray 110. Edge 114 has a bottomportion and two side portions defining an open rectangular crosssection. On top of edge 114 is a sealing layer 116 made of expandable,compressible, or other suitable material. When tray 110 is placed intocontainer 2, an exterior periphery of tray 110 will seat on edge 114 andlayer 116. The second part of interface 52 can be a removable plate 118having an edge 120 shaped to fit the shape of an interior periphery oftray 110. On top of edge 120 is a sealing layer 122 made of expandable,compressible, or other suitable material. Plate 118 is inserted intotray 110 along an interior periphery of tray 110. A guide rail can beprovided with tray 110 to guide plate 118 moving along an predeterminedinterior periphery. Different shapes can be used for edge 114 of seat112 and edge 120 of plate 118, as long as the shape matches that of theexterior and interior periphery of tray 110. For example, in oneembodiment, the open rectangular formed by edge 114 and edge 120 shownin FIG. 7b is modified by making the upper edge longer than the bottomedge of the open rectangular and tray 110 has a corresponding shape.This configuration makes it easier to the plate 118 down into tray 110and seal it. Plate 118 can further include an opening 56 of any kind asdiscussed previously with FIGS. 3b-3 g. Opening 56 can be located inplate 118 or on edge 120 facing the bottom of tray 110 where lumendevice is placed. In one embodiment, a layer of expandable,compressible, or other suitable sealing material is also provided withtray 110 along the interior periphery where plate 118 is inserted. FIG.7c shows another embodiment in which tray 110 has a partition 111therein. Partition 111 can be made as part of the tray 110. Upper edge111 a of partition 111 has a layer of expandable, compressible, or othersuitable sealing material. Partition 111 is aligned with plate 118 sothat when plate 118 is inserted into tray 110 seal can achieved betweenupper edge 11 a of partition 111 and lower edge of plate 118, and alumen device can be placed through the gap or opening 56 formed betweenupper edge 111 a of partition 111 and lower edge of plate 118. In oneembodiment, in the contact area between tray 110 and interface 52 (orplate 112 and 118), a portion of side and bottom walls of tray 110 isremoved so that in those portion the sealing layer 116 of tray seat 112and the sealing layer 122 of plate 118 of the interface 52 are in directcontact. Plate 118 can be secured to a lid or cover 119 for container 2and, a portion of the lower surface of the cover 119 is provided with alayer of expandable, compressible, or other suitable sealing material toseal the upper edge of the tray 110 and the container 2 as shown in FIG.7c.

[0080] When exposed to a pressure difference between enclosure 50 a and50 b, tray 110 may be forced to move from high pressure side to lowpressure side. In order to prevent this from happening, a stoppermechanism is provided. In one embodiment as shown in FIGS. 8a-8 d whichare top views of container 2 and tray 110, tray 110 has a rectangularbottom wall 130 with two side walls 132 along two longer edges of bottomwall 130 and two side walls 134 along two shorter edges of bottom wall130. There is an indentation on each side wall 132 extending along theentire height of side wall 132 and substantially perpendicular to bottomwall 130. Container 2 also has a rectangular bottom wall 140 with twoside walls 142 along the two longer edges of bottom wall 140 and twoside walls 141 along two shorter edges of bottom wall 140. There is aprojection 144 on each side wall 142 extending along the entire heightof side wall 142 and perpendicular to bottom wall 140. The surface ofprojection 144 is covered with a layer of expandable, compressible, orother suitable sealing material 146. The projection 144 has a shapematching that of the indentation 136. When tray 110 is placed intocontainer 2, indentation 136 will engage with projection 146 so as tohold tray 110 in position. A tray seat 112 with a layer of sealingmaterial on its upper surface is provided on bottom wall 140 ofcontainer 2 extending between two projections 146. Tray 110 also has twoedges 137 on each side wall 132 extending inwardly from indentation 136.A removable plate 118 with a layer of sealing material on its contactedge is inserted into tray 110 through a rail defined by extruding edge137. In another embodiment, each side wall 141 is provided with astopper, such as an extrusion, to confine the movement of tray 110 alonga direction perpendicular to interface 52.

[0081]FIG. 9 shows a recycling system which can be incorporated into anycontainer systems used in the present invention. In this system, usedliquid in a cleaning/sterilizing process is drained or pumped to areservoir 150 through a filter 152. A pump 154 can be provided betweenreservoir 150 and fluid port 6 to help drain the used liquid intoreservoir 150. The filtered liquid in reservoir 150 can be then cycledback to container 2 through a fluid port 6 a. If necessary, filter 152can be cleaned by back flash. Reservoir 150 is also equipped withseveral inlets 156 for water, cleaning chemical, and sterilant,respectively, and a drain 158.

[0082] The present invention has been described above. Manymodifications and variation of the cleaning/sterilizing orcleaning/disinfecting process and the apparatus in such process may bemade without departing substantially from the spirit and scope of thepresent invention. Accordingly, it should be clearly understood that theform of the invention described and illustrated herein is exemplaryonly, and is not intended as a limitation on the scope.

What is claimed is:
 1. A method for cleaning and sterilizing a medical device comprising the steps of: placing the device into a container; cleaning the device in the container with a cleaning solution; rinsing the device in the container with a rinse solution; vaporizing a liquid substance in the container to create a sterilant vapor and contacting the device with the vapor to effect sterilization of the device.
 2. A method according to claim 1 further comprising storing the device in the container in sterile form.
 3. A method according to claim 1 wherein the liquid substance comprises a retained portion of the rinse solution.
 4. A method according to claim 1 wherein the rinse solution comprises a chemical sterilant.
 5. A method according to claim 4 wherein the chemical sterilant comprises hydrogen peroxide.
 6. A method according to claim 1 wherein the liquid substance comprises a chemical sterilant.
 7. A method according to claim 6 wherein the chemical sterilant comprises hydrogen peroxide.
 8. A method according to claim 1 and further comprising introducing the liquid substance as a mist. 